How to Troubleshoot Wi-Fi Connection Problems on an iPhone
If you experience Wi-Fi connectivity issues on your iPhone, you may need to reset the Wi-Fi connection. Your connectivity issues could be caused by the wrong password if you are having trouble logging into the Wi-Fi network or from a problem in your iPhone's settings. By resetting the Wi-Fi connection, you are clearing out the previous settings created when you first connected to the network.
Tap the Settings icon on the iPhone's home screen, and tap the Wi-Fi tab. Swipe the switch on the Wi-Fi tab to ensure Wi-Fi is enabled on your iPhone.
Tap the blue arrow button on the network tab you are connected to in the network list, and tap "Forget this Network." Tap the "Forget Network" button that appears on the pop-up menu to confirm the action.
Tap the Wi-Fi Networks tab in the upper-left corner to return to the previous screen, and tap the network's tab in the network list to re-join it. Press the Home button on the iPhone, and tap the Safari icon on the home screen to test the Wi-Fi connection.
Tap the blue arrow icon on the network's tab if the connectivity problem persists, and tap the "Renew Lease" button at the bottom of the network's window.
Tap the "Renew Lease" button on the pop-up box to confirm the action.
Tap the Home button on the iPhone, and tap the Safari icon on the home screen to test the network connection.